Shift element subassemblies for transmissions, especially for automatic transmissions or automated shifting transmissions, are known in many ways. Thus, DE 199 32 614 A1 describes an arrangement of two axially adjacent shift elements constructed as a brake for a stepped automatic transmission. Here a joint disc carrier is provided for both brakes which is connected form-locking with the transmission housing and has a central partition axially between the two brakes. The pistons for hydraulic actuation of the respective brake are in each case arranged directly to the left and right of the partition, whereby one of the brakes is actuated through a double piston with two pressure chambers. Each brake has a resetting element constructed as a teller spring on a smaller diameter than the internal diameter of the disc, radially arranged beneath the disc friction area.
Friedrich J. Ehrlinger/Walter Kuhn, “The Automatic ZF Transmission HP 500” in ATZ Automotive Engineering Journal 79 (10) (1977), pp. 463-466 discloses a representative shift element subassembly of a stepped automatic transmission with two axially arranged adjacent transmission brakes which can be hydraulically actuated independently of each other. A joint disc carrier for accommodating the external discs of both brakes is provided for these two brakes. The discs of both brakes are arranged axially adjacent inside the disc carrier and are separated from each other by a central partition of the disc carrier. Both brakes respectively have a piston for hydraulic actuation which is in each case arranged on the side of the discs of the respective brake facing away from the partition. A joint resetting element constructed as a set of spiral springs is provided radially above the discs of both brakes for both pistons. The air-play adjustment of both brakes requires a plotting of the actual installation dimensions in the transmission housing.
The object of the invention is to perfect a shift element subassembly with two axially adjacent shift elements which can be actuated hydraulically or pneumatically independently of each other with respect to the smallest possible construction space and with respect to installation friendliness.